Features and Improvements
- Transient Stability: Added code with a Distributed Generation model which specifies a FilterPmin, FilterPQMin, and FilterVmin as filters of when to use the specified Distributed Generation model. When loading a _cmpldw2 model, the distributed generation model created from any dgpv or dgder_a models inside the modulate CompLoad will use the Pmin of the load model divided by 5.
- General: Prior to this patch, DC lines could be defined inside the user interface with duplicate Num ID when their Rectifier and Inverter bus numbers were reversed. This has been changed such that these two objects cannot be simultaneously present.
DCTransmissionLine '615600' '615353' '1'
DCTransmissionLine '615353' '615600' '1'
Instead, a new Num ID must be chosen for the later object, such that:
DCTransmissionLine '615600' '615353' '1'
DCTransmissionLine '615353' '615600' '2'
This change does not impact reading from an AUX file, because this was already being enforced. However, this change does impact defining a DC line object from the user interface, and also while reopening a PWB file that might have duplicate Num IDs.
- Optimal Power Flow (OPF): In OPF, the island constraint equation was not being formed correctly leading to oscillating dispatches in the OPF. In the equation, the scheduled export quantity for the island was being entered in MW, instead of per-unit. This caused the island equality constaints to be off by a factor of the system MVA base, hence giving a bad OPF solution.
- Power Flow Solution: Bug fix for the DC tie line list for areas, zones and super areas that was not being populated correctly when there were 2 DC lines defined across the same two AC buses, with the same Num ID, but with the Rect/Inv buses transposed. This would affect the ACE calculation and cause the power flow to shift upon resolving.
- Transient Stability: It was possible to get access violations when running distributed power flow contingency analysis and monitoring transient stability models. This has been fixed.